The ECHONET Lite Specifications and the Workof the ECHONET Consortium
Hisashi Kodama

Managing Director
ECHONET Consortium

1. Introduction
To realize a sustainable society, it is important to take on thehousehold sector where energy consumption is continuing toincrease. In recent years, there have also been rapid advances in thespread of systems that can help reduce energy consumption. Theseinclude not only energy-saving appliances, but also energy-creation
systems such as photovoltaic solar panels and fuel cells, and energystorage devices such as batteries. This is adding to the complexity ofusing energy efficiently in the home.
It is therefore essential to introduce HEMS (Home EnergyManagement Systems) that can control these devices to achieve
efficient operation, which means it is vital that all manufacturers
provide controllers and appliances that use a standardized interface.
This article presents an overview of the ECHONET Litespecifications,[1] which define an open standard interface for smart■ Figure 1: Support services provided by ECHONET

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house equipment, and introduces the activities of the ECHONET
Consortium, which drew up these specifications and is working to
spread and promote smart house systems.

2. Past work of the ECHONET Consortium
ECHONET Lite is an open communication protocolthat supports smart houses and HEMS. Although there had
previously been means-based discussions on how equipment could
be connected over a network, these resulted in standards based
applications and needs, and standardization was promoted fromdiscussions on what sort of world we were trying to create, and how
to go about realizing it. In fact, six application domains such asenergy management and home healthcare were established, and theaim was to devise specifications that enable the provision of services
that can resolve social issues in these domains. Figure 1 shows the■ Figure 2: The ECHONET Lite and ECHONET specifications
support services that are provided byECHONET.
The origins of the ECHONET
Consortium can be traced back tothe Scientific Research Committee
on 21st Century Home Networks(October 1996 – May 1997), which
consisted of businesses in theelectrical and domestic appliancesectors. In June 1997, it asked theMinistry of Economy, Trade andIndustry (then known as the Ministryof International Trade and Industry)
to promote the development andinternational standardization ofnetworks supporting equipment frommultiple vendors. The ECHONET
C onsor t iu m w a s fou nded i nDecember 1997 in order to carryout this work. Since then, with
the nation's support behind it, theby the committee in July 2011. In the following December, theConsortium has continued to work on drafting specifications
ECHONET Lite specifications were opened to the general public,
and promoting the spread of smart house technology. Today its
making it an open standard both by name and by nature.
membership comprises over 240 companies.
Our specifications can be broadly classified into two types:
3. ECHONET device objects
the ECHONET specifications and the ECHONET LiteThe basis of the ECHONET specifications is the idea of aspecifications. Figure 2 shows their respective protocol stacks.
deviceobject, which is described below.
The first version of the ECHONET specifications was drawn
Itisenvisaged that household networks will be used to connect
up in 1999, and by 2009 it finally became an international standard.
awidevarietyof equipment sold by many different manufacturers,
This process models consumer electrical equipment and facilities as
so what is actually needed is compatibility between diverse systems.
objects and standardizes the protocols to form a basic framework
This is harder to achieve than with business systems, which arefor ECHONET. At that time, there were no communicationeasier to manage. Take air conditioners, for example. The methods
media that could be used in the home without carrying out
used to implement functions with embedded software based on
installation work, so we developed our own communication media
measurement data from a group of sensors will differ from oneusing specified low-power radio communication and power line
manufacturer to the next, and even from one product to the next.
communication, and specified its structure for all seven layers of

the OSI model.
But since then, substantial
developments were madew it h v a r iou s for ms ofcommunication media, andthere were also many calls
for adding Internet Protocol
support and allowing free useof communication media.
As a result, the specification
was pulled back to define
only layers 5 through 7 of theOSI model, and the transportlayer was left free so that IP
addresses can be used. [2] To
facilitate the installation ofgreater numbers of devices, wealso drew up the ECHONET
Lite specifications with aslimmed-down middleware
section. These were published■ Figure 3: Overview of ECHONET device object

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■ Figure 4: ECHONET device object types

Organization for Standardization)and IEC (International Electrotechnical Commission). Specifically, theECHONET specifications are divided into six parts, and are proposed
via two routes: IEC TC100, andISO/IEC JTC1/SC25/WG1. TheECHONET device object became
an international standard in October
2013, and work on the ECHONET
Lite protocol is also continuing witha view to achieving standardization
early in the 2015 business year.
IEC TC57 is also working
to sta nda rd iz e t he inter facespecifications between smart grids
and customers, and is raising theinternational profile of ECHONET
Lite by proposing use cases thatinvolve these specifications.

To enable all air conditioners to be represented in a common
manner, they have to be standardized as device objects based on an5. Promotion of ECHONET Liteabstract model. By accessing and controlling the property valuesThe Ministry of Economy, Trade and Industry is promotingof this standardized object, an application program can provide
standardization relating to smart houses to respond to calls fromcompatibility with all air conditioners without any modifications.
society for greater energy savings, and has therefore started up
Figure 3 shows an outline of an ECHONET device object.
the “JSCA International Standardization WG Smart HouseECHONET device objects offer more than just simple
Standardization Working Group”. At the third study meetinginteraction at the remote control command level (like “ON/OFF”
held in February 2012, ECHONET Lite was recommended asbuttons), but also standardize the functions of highly sophisticatedthe standard interface between HEMS (controllers) and domesticequipment, making it possible to implement the advanced control
equipment, and between HEMS and smart meters.[4] Thus, sinceneeded by energy management applications.
April 2012, each manufacturer has started investing in the market
Figure 4 shows an example of a defined device object.[3]for ECHONET Lite equipment. After that, a “JSCA Smart
Currently, over 90 different kinds of ECHONET device objects
House/Building Standards/Business Promotion Study Group”
have been defined. These include security-related devices such(the successor of the abovementioned committee) was establishedas fire sensors and human detection sensors, energy-consuming
in June 2012. This Study Group defines eight key equipment
domestic equipment such as air■ Figure 5: International standardization activities
conditioners and lighting, andequipment for the creation and storageof energy, such as photovoltaic power
generation systems, domestic fuelcells and domestic storage batteries.
Members of t he ECHONET
Consortium have proposed revisions
to the device object in order to adapt
to new devices, and a permanentworking group of experts for drafting
new functions has been proposed andis continuing to expand.

4. Internationalstandardization
Figure 5 shows the progress madein international standardization of theECHONET Lite specifications. TheECHONET Consortium is engaged
in de jure standardization activities
sanctioned by the ISO (International6

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■ Figure 6: Number of certified ECHONET Lite devices (as of December2014)
categories for smart
houses (smart meters,photo v olt a ic s ol a rpanels, storage batteries,
fuel cell, electric vehicle
charging systems, airconditioners, lighting,and water heaters),
formulates operationalg uidelines for thise q u i p m e n t , [5 ] a n dpromotes the spreadof HEMS equipment.
To support productdevelopment in eachcompany, the HEMS(ECHONET Lite)
Certification Support
Center was established in the Kanagawa Institute of Technology
respond to the needs of companies over a wide range of activities.
to support certification applications for equipment developed using
Through our efforts to spread ECHONET Lite specifications
the ECHONET Lite specifications, and to provide a productand products, we hope that the consortium will contribute to thedevelopment environment and interconnection environment.
realization of a smart, sustainable society by exploiting the benefits
Figure 6 shows the number of items of ECHONET Liteof consumer electrical equipment and household facilities that haveequipment that have so far been certified (as of December 2014).
been cultivated in Japan so far in order to promote international
Through the above-mentioned cooperative efforts of industry,business development.
government and academia to promote the spread of smart houses,REFERENCES
it can be seen that the market penetration of HEMS equipment[1] ECHONET Consortium: ECHONET Lite Specification Ver.1.11, http://www.echonet.gr.jp/spec/(controllers and energy visualization) is being promoted. Thus, the[2] The Telecommunication Technology Committee: TR-1043 home network communication
introduction of HEMS equipment is currently being advanced as ainterface implementation guidelines[3] ECHONET Consortium: APPENDIX, Detailed Requirements for ECHONET Device Objects,
step towards the spread of smart houses.
Release F, http://www.echonet.gr.jp/spec/
However, realizing true smart houses involves more than[4] Ministry of Economy, Trade and Industry: Collected publications of the JSCA InternationalStandardization WG, Smart House Standardization Study Group, http://www.meti.go.jp/prejust energy savings through visualization. It is also necessary
ss/2011/02/20120224007/20120224007.html
to optimally control the energy creation equipment and energy[5] Ministry of Economy, Trade and Industry: Smart House Building Standards and Business
Promotion Study Group (4th) handouts, http://www.meti.go.jp/committee/kenkyukai/
storage equipment for an even greater effect, and to offer services
shoujo/smart_house/004_haifu.html
that enable the user to feel the benefits of this technology. In thefuture, as the next step, we will strengthen our efforts to facilitatecontributions to the promotion of commercialization by member
companies, such as rapid investment in the market for equipmenton the controlled side, and support for commercialization of theeight key equipment categories.
It is also essential to ensure interoperability in order to promote
Cover Artthe spread of these devices. At the ECHONET Consortium, weare working on a certification system for ECHONET Lite bydrawing up certification specifications and accrediting third-party
certification organizations. We are also working on to help member
companies with product development and certification by holding
Meisho Edo Hyakkei
regular events called Plugfests that give people the opportunity toSumidagawa Suijin nomori Massaki
actually try out interconnectivity with equipment from multiple(Suijin Shrine and Massaki
vendors.
on the Sumida River,

6. Conclusion
In this article, I have introduced the ECHONET Litespecification, which provides an open standard interface forsmart houses, and the activities of the ECHONET Consortium.
In April 2014, the ECHONET Consortium changed from a
private organization into a general incorporated association. As
we strengthen our systems, we intend to work harder than ever tofrom the series One Hundred
Famous Views of Edo)

Utagawa Hiroshige (1797-1858)

Woodblock print:
Courtesy of Sakai Kokodo Gallery

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